Movie 4.

Representative single plane spinning disk microscopy time lapse demonstrating collapse of endo-lysosomal tubules with associated pH collapse in LLOMe. Primary mouse embryonic fibroblasts were loaded with 5μg/mL DQ-BSA for 16 hours, then chased for 2 hours. Following chase, cells were then loaded with 100μg/mL10kDa fluorescein (FITC) dextran for 30 minutes, without additional chase. Time lapse was captured for 7 minutes at 3 sec per frame. 1mM LLOMe was added directly to stage at 2 minutes indicated by black frames. White arrows indicate examples of collapsing tubules with associated pH neutralization following LLOMe addition. Scale bar = 10μm, frame rate = 20fps.